1. Field of the Invention
The invention relates in general to conveyors and in particular to a new and useful bucket conveyor having an endless traction drive cable which is guided over drive and guide pulleys and around spaced apart guide pins and bucket pulleys of each bucket carried by the traction cable.
2. Description of the Prior Art
Bucket conveyors are mostly used to transport bulk material in vertical or horizontal directions, a constantaly pulsating material current being achieved with a plurality of buckets, troughs or pockets. The buckets, troughs or pockets receiving the material to be conveyed are secured on endless traction means or endless conveyors and form with the conveyors a barrow tram. In the presently known designs, the traction means comprise either chains of various design or traction belts with or without inserts. Thus German Pat. Nos. 528,451 and 173,388 show belt conveyors and the fastening of the buckets on the latter, while German Pat. No. 625,808 and DOS 1,556,173 show chains as a traction means in bucket conveyors.
For the heavy-duty bucket conveyors required today, these designs are not longer suitable. The conveyor current sizes under discussion today start at 500 t/h, and are already at 1000 t/h, and will far exceed this size in the future (1600 t/h). Here belts as traction means are no longer sufficient. The belt thickness necessary for higher conveyor volumes considerably increases the existing dead loads. The drum diameters must likewise be increased at the expense of added weight. The fastening of the buckets on the belt becomes more difficult.
The use of chain traction means can be eliminated from the beginning, because the increased output of a bucket conveyoer can be achieved substantially only by increasing the conveying speed. Round link chains permit only speeds of up to a maximum of 0.8 m/s, sprocket chains up to a maximum of 2.5 m/s. With these speeds the chains are soon worn out. At higher speeds the use of chains is no longer economically feasible.